/**
 * Copyright (c) 2010, Casey Lai
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 * 
 * Neither the name of the Cheetah Group nor the names of its contributors may be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

package org.cheetahworkflow.engine;

import java.io.InputStream;

/**
 * this class is the executor of workflow system
 * @author caseylai
 * @param <T> context
 */
public class WorkflowExecutor<T> {
	
	private final WorkflowConfigure<T> config;
	
	/**
	 * get instance of executor
	 * @param in configure file input stream
	 */
	public WorkflowExecutor(InputStream in) {
		config = new WorkflowConfigure<T>(in);
	}
	
	/**
	 * execute one workflow
	 * @param input context, parameter of the execute
	 * @throws Exception any exception thrown from the internal logic
	 */
	public void exec(T context) throws Exception {
		WorkflowNodeEntry<T> entry = config.getEntry(Constants.NODE_START);
		while ((entry = entry.exec(context)) != null);
	}
}
